Multiplexed Optical Imaging of Tumor-Directed Nanoparticles: A Review of Imaging Systems and Approaches

Abstract

In recent decades, various classes of nanoparticles have been developed for optical imaging of cancers. Many of these nanoparticles are designed to specifically target tumor sites, and specific cancer biomarkers, to facilitate the visualization of tumors. However, one challenge for accurate detection of tumors is that the molecular profiles of most cancers vary greatly between patients as well as spatially and temporally within a single tumor mass. To overcome this challenge, certain nanoparticles and imaging systems have been developed to enable multiplexed imaging of large panels of cancer biomarkers. Multiplexed molecular imaging can potentially enable sensitive tumor detection, precise delineation of tumors during interventional procedures, and the prediction/monitoring of therapy response. In this review, we summarize recent advances in systems that have been developed for the imaging of optical nanoparticles that can be heavily multiplexed, which include surface-enhanced Raman-scattering nanoparticles (SERS NPs) and quantum dots (QDs). In addition to surveying the optical properties of these various types of nanoparticles, and the most-popular multiplexed imaging approaches that have been employed, representative preclinical and clinical imaging studies are also highlighted.

Application of Nanomaterials in Biomedical Imaging and Cancer Therapy

“…The broad absorption spectra and large stokes shifts of quantum dots allow simultaneous imaging of multiple types of quantum dots with single wavelength excitation. Quantum dots are also often coupled to a biomolecule for targeted imaging [ 84 ]. Lead sulfide quantum dots with 1100 nm emission peaks can be used in NIR fluorescence imaging of cerebral venous thrombosis.…”

Recent advances in the development of nanoparticles for multimodality imaging and therapy of cancer

“…Imaging probes are being developed for use as directly‐visualized agents, include intraoperative imaging tools to help localize tumors with or without the use of a traditional imaging platform such as CT, MRI, PET, and so on. Examples include the use of fluorescent probes, Raman‐scattering (SERS), polymer dots and quantum dots (QD) . For example, a liposomal encapsulated iodohexal (an iodinated contrast agent) was conjugated to an ICG, which allowed both preoperative and intraoperative tumor localization in rabbit lung cancer models.…”

Multiplex detection of ctDNA mutations in plasma of colorectal cancer patients by PCR/SERS assay

“…SERS is a vibrational spectroscopic technique for probing molecules on or near the nanoscale surface of metallic substrates, which enables a rapid, sensitive and non-destructive detection of the target molecules with characteristic spectra via localized surface plasmon resonances [21][22][23][24]. Recently, SERS nanotags as a new class of label have demonstrated unique and attractive applications in biological labelling with key advantages including ultra-sensitivity (down to single molecule under certain conditions), suitability for multiplexing due to the narrow width of vibrational Raman bands, quantification based on spectral intensities, high photostability, minimal autofluorescence from biological specimens via red to near-infrared (NIR) laser excitation, and the requirement for only single laser source for excitation [21,22,[25][26][27]. The multiplexing capability is potentially very useful for screening multiple mutations from limited samples, such as ctDNA.…”